The present invention relates to a retainer assembly for use with a stroking universal joint and method for retaining a stroking universal joint.
More specifically, the present invention relates to a novel retaining ring and groove assembly used to retain a spider assembly within a housing in a tripot type universal joint.
Stroking universal joints for use in connection with constant velocity joints are well known in the art. One such type of stroking joint is a tripot type. Very generally, a tripot type universal joint includes a housing defining a plurality of elongated drive channels and a spider assembly retained within the housing. The spider assembly includes rollers disposed in the drive channels for allowing relative longitudinal movement between the spiders and the housing. A splined shaft is typically connected to an interior hub in the spider assembly. Similarly, a splined shaft is connected to the housing. Relative rotational movement is transmitted between the splined shafts through the spider and housing assembly. The spider assembly allows for relative longitudinal movement between the two splined shafts. This axial movement or stroke is required for changes in distance during normal suspension movement.
The tripot type joint requires the aid of some type of retention method to retain the spider assembly within the tripot housing. Known retention methods include the use of a wire ring, staking of the drive channels to prevent the spider assembly moving therepast or a stamping. All of these methods require assembly after the spider is inserted into the housing during final assembly of the constant velocity joint. Such assembly processes are relatively more complex, therefore, adding time and effort to the assembly process.
One such wire ring is shown in U.S. Pat. No. 4,516,957 to Chyz, et al. Another such retainer is shown in U.S. Pat. No. 4,437,219 to Dore.
According to the present invention, there is provided a retainer assembly for use in a stroking universal joint of the type having an inner drive spider assembly with a plurality of circumferentially spaced trunnions, an outer drive housing member having an interior wall surrounding the spider assembly. A plurality of elongated drive channels is in the interior wall of the housing wall member. Each of the trunnions has a drive roller rotatably mounted thereon and respectively disposed for linear travel in an associate one of the drive channels. The retainer assembly comprises a retaining ring adapted to be mounted in the other drive assembly for movement between compressed and uncompressed states to retain the inner drive spider assembly therein when in the uncompressed state. The retaining ring has first generally planar small diameter segments and second generally planar large diameter segments. The first small diameter segments are axially offset from the large diameter segments. The first diameter segments and the second diameter segments are connected by blocking segments. The assembly further comprises an annular groove in the interior wall of the housing member. The annular groove includes a deep groove portion and at least one retaining ring movement portion for allowing movement of the retaining ring therein.
A method for retaining a stroking universal joint of the type having an inner drive spider with a plurality of circumferentially spaced trunnions and an outer drive housing member having an inner wall surrounding the spider assembly is also provided. The spider assembly used in the method has a plurality of elongated drive channels in the interior wall of the housing. Each of the trunnions has a drive roller rotatably mounted thereon. The method comprises the steps of providing the housing member with an annular groove in the interior wall thereof. The annular groove includes at least one retaining ring movement portion for allowing movement of a retaining ring therein. The method further comprises inserting a retaining ring, having first generally planar small diameter segments and second generally planar large diameter segments, the first small diameter and second large diameter segments being axially offset from each other and connected by blocking segments, into the annular groove, such that at least a portion of the blocking segments lies within the drive channel in an uncompressed state. The spider assembly is further inserted into the housing by placing the rollers into the drive channels. A force is applied to the spider assembly sufficient to move the retaining ring to a compressed state wherein the blocking segments move out of the drive channels. The spider assembly is further inserted into the housing past the retaining ring until the retaining ring returns to the uncompressed state.
Accordingly, it is an object of the present invention to provide a pre-assembled retaining ring within the housing before assembly of the spider with the housing which pre-assembled retaining ring allows the spider assembly to be inserted into the housing and then retained therein by the retaining ring.
It is another object of the present invention to provide a retainer that is moved in response to an insertion force supplied by the spider to the ring allowing movement of the retaining ring in a groove and providing a ring that locks in position once the spider assembly has been sufficiently moved into the housing.
It is another object of the present invention to provide a specific grooved geometry that allows movement of the retaining ring during insertion of the spider assembly but prevents movement of the retaining ring once the spider assembly has been moved into the housing.
It is another object of the present invention to provide a pre-assembled retainer system that does not require any further fabrication once the spider assembly is moved to within the housing.
It is another object of the present invention to provide a wire retainer assembly within the end of the housing to retain the spider assembly therein which does not substantially add to the bulk or weight of the joint and which can be easily and repeatedly removed and reinstalled.
Another object of the present invention is to provide a new and improved retainer assembly for use in a tripot joint for retaining the spider assembly and which has a retaining ring fit within a groove in the housing which is adapted to stop the rollers at their full out position without detracting from effective and efficient operation of the spider during drive transmission.